The External Innovative Network Core brings together small teams of investigators to work in collaboration with one another on complex areas of inquiry. Some of these projects are cross-national and involve the co laborative engagement of investigators from multiple countries. In these projects, the laim is to address a common issue, while learning from the diverse policies, institutions and experience of ithese different countries. The cross-national projects are often organized around a set of parallel investigations in each country, enabling more meaningful comparisons across countries. Other projects focus on issues in aging in the United States where a multi-faceted investigation can be fruitful. For these projects, each member of the collaborative group looks at a different but related aspect of the broader subject.